pmlpp/mlpp/probit_reg/probit_reg.cpp

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//
// ProbitReg.cpp
//
// Created by Marc Melikyan on 10/2/20.
//
2023-01-24 18:12:23 +01:00
#include "probit_reg.h"
#include "../activation/activation.h"
#include "../lin_alg/lin_alg.h"
#include "../regularization/reg.h"
#include "../utilities/utilities.h"
#include "../cost/cost.h"
#include <iostream>
#include <random>
namespace MLPP{
ProbitReg::ProbitReg(std::vector<std::vector<double>> inputSet, std::vector<double> outputSet, std::string reg, double lambda, double alpha)
: inputSet(inputSet), outputSet(outputSet), n(inputSet.size()), k(inputSet[0].size()), reg(reg), lambda(lambda), alpha(alpha)
{
y_hat.resize(n);
weights = Utilities::weightInitialization(k);
bias = Utilities::biasInitialization();
}
std::vector<double> ProbitReg::modelSetTest(std::vector<std::vector<double>> X){
return Evaluate(X);
}
double ProbitReg::modelTest(std::vector<double> x){
return Evaluate(x);
}
void ProbitReg::gradientDescent(double learning_rate, int max_epoch, bool UI){
Activation avn;
LinAlg alg;
Reg regularization;
double cost_prev = 0;
int epoch = 1;
forwardPass();
while(true){
cost_prev = Cost(y_hat, outputSet);
std::vector<double> error = alg.subtraction(y_hat, outputSet);
// Calculating the weight gradients
weights = alg.subtraction(weights, alg.scalarMultiply(learning_rate/n, alg.mat_vec_mult(alg.transpose(inputSet), alg.hadamard_product(error, avn.gaussianCDF(z, 1)))));
weights = regularization.regWeights(weights, lambda, alpha, reg);
// Calculating the bias gradients
bias -= learning_rate * alg.sum_elements(alg.hadamard_product(error, avn.gaussianCDF(z, 1))) / n;
forwardPass();
if(UI) {
Utilities::CostInfo(epoch, cost_prev, Cost(y_hat, outputSet));
Utilities::UI(weights, bias);
}
epoch++;
if(epoch > max_epoch) { break; }
}
}
void ProbitReg::MLE(double learning_rate, int max_epoch, bool UI){
Activation avn;
LinAlg alg;
Reg regularization;
double cost_prev = 0;
int epoch = 1;
forwardPass();
while(true){
cost_prev = Cost(y_hat, outputSet);
std::vector<double> error = alg.subtraction(outputSet, y_hat);
// Calculating the weight gradients
weights = alg.addition(weights, alg.scalarMultiply(learning_rate/n, alg.mat_vec_mult(alg.transpose(inputSet), alg.hadamard_product(error, avn.gaussianCDF(z, 1)))));
weights = regularization.regWeights(weights, lambda, alpha, reg);
// Calculating the bias gradients
bias += learning_rate * alg.sum_elements(alg.hadamard_product(error, avn.gaussianCDF(z, 1))) / n;
forwardPass();
if(UI) {
Utilities::CostInfo(epoch, cost_prev, Cost(y_hat, outputSet));
Utilities::UI(weights, bias);
}
epoch++;
if(epoch > max_epoch) { break; }
}
}
void ProbitReg::SGD(double learning_rate, int max_epoch, bool UI){
// NOTE: ∂y_hat/∂z is sparse
Activation avn;
LinAlg alg;
Reg regularization;
double cost_prev = 0;
int epoch = 1;
while(true){
std::random_device rd;
std::default_random_engine generator(rd());
std::uniform_int_distribution<int> distribution(0, int(n - 1));
int outputIndex = distribution(generator);
double y_hat = Evaluate(inputSet[outputIndex]);
double z = propagate(inputSet[outputIndex]);
cost_prev = Cost({y_hat}, {outputSet[outputIndex]});
double error = y_hat - outputSet[outputIndex];
// Weight Updation
weights = alg.subtraction(weights, alg.scalarMultiply(learning_rate * error * ((1 / sqrt(2 * M_PI)) * exp(-z * z / 2)), inputSet[outputIndex]));
weights = regularization.regWeights(weights, lambda, alpha, reg);
// Bias updation
bias -= learning_rate * error * ((1 / sqrt(2 * M_PI)) * exp(-z * z / 2));
y_hat = Evaluate({inputSet[outputIndex]});
if(UI) {
Utilities::CostInfo(epoch, cost_prev, Cost({y_hat}, {outputSet[outputIndex]}));
Utilities::UI(weights, bias);
}
epoch++;
if(epoch > max_epoch) { break; }
}
forwardPass();
}
void ProbitReg::MBGD(double learning_rate, int max_epoch, int mini_batch_size, bool UI){
Activation avn;
LinAlg alg;
Reg regularization;
double cost_prev = 0;
int epoch = 1;
// Creating the mini-batches
int n_mini_batch = n/mini_batch_size;
auto [inputMiniBatches, outputMiniBatches] = Utilities::createMiniBatches(inputSet, outputSet, n_mini_batch);
// Creating the mini-batches
for(int i = 0; i < n_mini_batch; i++){
std::vector<std::vector<double>> currentInputSet;
std::vector<double> currentOutputSet;
for(int j = 0; j < n/n_mini_batch; j++){
currentInputSet.push_back(inputSet[n/n_mini_batch * i + j]);
currentOutputSet.push_back(outputSet[n/n_mini_batch * i + j]);
}
inputMiniBatches.push_back(currentInputSet);
outputMiniBatches.push_back(currentOutputSet);
}
if(double(n)/double(n_mini_batch) - int(n/n_mini_batch) != 0){
for(int i = 0; i < n - n/n_mini_batch * n_mini_batch; i++){
inputMiniBatches[n_mini_batch - 1].push_back(inputSet[n/n_mini_batch * n_mini_batch + i]);
outputMiniBatches[n_mini_batch - 1].push_back(outputSet[n/n_mini_batch * n_mini_batch + i]);
}
}
while(true){
for(int i = 0; i < n_mini_batch; i++){
std::vector<double> y_hat = Evaluate(inputMiniBatches[i]);
std::vector<double> z = propagate(inputMiniBatches[i]);
cost_prev = Cost(y_hat, outputMiniBatches[i]);
std::vector<double> error = alg.subtraction(y_hat, outputMiniBatches[i]);
// Calculating the weight gradients
weights = alg.subtraction(weights, alg.scalarMultiply(learning_rate/outputMiniBatches.size(), alg.mat_vec_mult(alg.transpose(inputMiniBatches[i]), alg.hadamard_product(error, avn.gaussianCDF(z, 1)))));
weights = regularization.regWeights(weights, lambda, alpha, reg);
// Calculating the bias gradients
bias -= learning_rate * alg.sum_elements(alg.hadamard_product(error, avn.gaussianCDF(z, 1))) / outputMiniBatches.size();
y_hat = Evaluate(inputMiniBatches[i]);
if(UI) {
Utilities::CostInfo(epoch, cost_prev, Cost(y_hat, outputMiniBatches[i]));
Utilities::UI(weights, bias);
}
}
epoch++;
if(epoch > max_epoch) { break; }
}
forwardPass();
}
double ProbitReg::score(){
Utilities util;
return util.performance(y_hat, outputSet);
}
void ProbitReg::save(std::string fileName){
Utilities util;
util.saveParameters(fileName, weights, bias);
}
double ProbitReg::Cost(std::vector <double> y_hat, std::vector<double> y){
Reg regularization;
class Cost cost;
return cost.MSE(y_hat, y) + regularization.regTerm(weights, lambda, alpha, reg);
}
std::vector<double> ProbitReg::Evaluate(std::vector<std::vector<double>> X){
LinAlg alg;
Activation avn;
return avn.gaussianCDF(alg.scalarAdd(bias, alg.mat_vec_mult(X, weights)));
}
std::vector<double>ProbitReg::propagate(std::vector<std::vector<double>> X){
LinAlg alg;
return alg.scalarAdd(bias, alg.mat_vec_mult(X, weights));
}
double ProbitReg::Evaluate(std::vector<double> x){
LinAlg alg;
Activation avn;
return avn.gaussianCDF(alg.dot(weights, x) + bias);
}
double ProbitReg::propagate(std::vector<double> x){
LinAlg alg;
return alg.dot(weights, x) + bias;
}
// gaussianCDF ( wTx + b )
void ProbitReg::forwardPass(){
LinAlg alg;
Activation avn;
z = propagate(inputSet);
y_hat = avn.gaussianCDF(z);
}
}